The long-term objectives of this project are to elucidate the mechanism of Herpes simplex virus (HSV) infection and to eliminate the recurrent infections that result from reactivation of latent virus. The specific aims of the proposal are to: (1) characterize neurons from the trigeminal ganglia according to various parameters which may be correlated with permissiveness or resistance to infection with HSV; (2) develop markers which can identify the presence of latent HSV; (3) improve treatment for acute and recurrent HSV infection by identification and development of new and/or improved biological and chemical antiviral agents such as interferons, nucleoside analogs, etc.; and (4) develop a non-human primate ocular model of recurrent HSV infection to study all of the above in a model that is closer to the human condition than the animal models previously studied. The health relatedness of the project is clear because an estimated 300,000 new cases of herpetic keratitis are reported in the United States each year. Latent virus becomes established in neurons that innervate the cornea; repeated spontaneous reactivation of the latent virus occurs in 25-50% of cases within two years and subsequent recurrences frequently leads to additional damage of ocular tissue with the increased risk of blindness. Better treatment of infections, inhibition of virus reactivation or eradication of latent virus from the neurons would eliminate the problems resulting from herpes virus. At present, numerous topical treatment regimens can reduce severity of ocular involvement but recurrences cannot be prevented and HSV cannot be eradicated from the nervous system. The methodology to be used to achieve the specific aims of this proposal include basic virus isolation procedure in addition to a combination of molecular, immunofluorescent and radiolabelled probes and immunocytochemical techniques using monoclonal antibodies, labelled lectins and horseradish peroxidase tracking with light and electron microscopy to identify latent HSV and the neuronal cells in which the virus establishes itself. Other techniques involve chemical reactivation of latent HSV concurrent with antiviral drug treatment to eradicate latent virus, use of neuron cell cultures as in vitro models of acute and latent infection. Additional specific methods to be used include, DNA hybridization, southern blotting, gel electrophoresis, immunoblot and radioimmunoprecipitation.